It is well established in microbiology that fungi have cell envelopes composed of a membrane and an outer cell wall. One component of fungal cell walls is a polysaccharide known as chitin (a homopolymer of N-acetyl-D-glucosamine in .beta.(1.fwdarw.4)linkage). Cell walls also contain large amounts of glucan and mannoprotein. Disruptions in the metabolic pathway leading to chitin synthesis or chemical or physical perturbations of the intact cell wall are desirable mechanisms for antifungal agents. Severe weaknesses or large discontinuities in the cell wall may lead to cytoplasmic leakage and cell death. Smaller holes in the cell wall may allow small regions of the cell membrane to "blow out" permitting usually excluded molecules to enter the cell. Consequently, the combination of a usually excluded cytoplasmically active antifungal agent with a localized cell wall perturbating agent can lead to death of the fungal cell.
The ability to screen compounds for cell envelope perturbating activity would be a useful means of identifying antifungal agents as well as understanding the mechanism of cell envelope synthesis and maintenance. The ideal screening system would be sensitive, specific, relatively rapid, and easy to read.